Clinical profiles of placenta accreta spectrum: the PACCRETA population-based study

[Maternal mortality due to obstetric haemorrhage in France 2016-2018]

Between 2016 and 2018, 20 maternal deaths were related to obstetric haemorrhage, excluding haemorrhage in the first trimester of pregnancy, representing a mortality ratio of 0.87 per 100,000 live births (95% CI 0.5 -1.3). Obstetric haemorrhage is the cause of 7.4% of all maternal deaths up to 1 year, 10% of maternal deaths within 42days, and 21% of deaths directly related to pregnancy (direct causes). Between 2001 and 2018, maternal mortality from obstetric haemorrhage has been considerably reduced, from 2.2deaths per 100,000 live births in 2001-2003 to 0.87 in the period presented here. Nevertheless, obstetric haemorrhage is still one of the main direct causes of maternal death, and remains the cause with the highest proportion of deaths considered probably (53%) or possibly (42%) preventable according to the CNEMM's collegial assessment (see chapter 3). The preventable factors reported are related to inadequate content of care in 94% of cases and/or organisation of care in 44% of cases. In this triennium, maternal death due to haemorrhage occurred mainly in the context of caesarean delivery (65% of cases, i.e. 13/20), and mostly in the context of emergency care (12/13). The main causes of obstetric haemorrhage were uterine rupture (6/20) in unscarred uterus or in association with placenta accreta, and surgical injury during the caesarean delivery (5/20). Every maternity hospital, whatever its resources and/or technical facilities, must be able to plan any obstetric haemorrhage situation that threatens the mother's vital prognosis. Intraperitoneal occult haemorrhage following caesarean section and uterine rupture require immediate surgery with the help of skilled surgeon resources with early and appropriate administration of blood products.

Assisted reproductive technology-associated risk factors for placenta accreta spectrum after vaginal delivery

This study aimed to investigate assisted reproductive technology (ART) factors associated with placenta accreta spectrum (PAS) after vaginal delivery. This was a registry-based retrospective cohort study using the Japanese national ART registry. Cases of live singleton infants born via vaginal delivery after single embryo transfer (ET) between 2007 and 2020 were included (n = 224,043). PAS was diagnosed in 1412 cases (0.63% of deliveries), including 1360 cases (96.3%) derived from frozen-thawed ET cycles and 52 (3.7%) following fresh ET. Among fresh ET cycles, assisted hatching (AH) (adjusted odds ratio [aOR], 2.5; 95% confidence interval [CI] 1.4-4.7) and blastocyst embryo transfer (aOR, 2.2; 95% CI 1.3-3.9) were associated with a significantly increased risk of PAS. For frozen-thawed ET cycles, hormone replacement cycles (HRCs) constituted the greatest risk factor (aOR, 11.4; 95% CI 8.7-15.0), with PAS occurring in 1.4% of all vaginal deliveries following HRC (1258/91,418 deliveries) compared with only 0.11% following natural cycles (55/47,936). AH was also associated with a significantly increased risk of PAS in frozen-thawed cycles (aOR, 1.2; 95% CI 1.02-1.3). Our findings indicate the need for additional care in the management of patients undergoing vaginal delivery following ART with HRC and AH.

Risk factors for placenta accreta spectrum disorders in women with any prior cesarean and a placenta previa or low lying: a prospective population-based study

This study aimed to identify the risk factors for placenta accreta spectrum (PAS) in women who had at least one previous cesarean delivery and a placenta previa or low-lying. The PACCRETA prospective population-based study took place in 12 regional perinatal networks from 2013 through 2015. All women with one or more prior cesareans and a placenta previa or low lying were included. Placenta accreta spectrum (PAS) was diagnosed at delivery according to standardized clinical and histological criteria. Of the 520,114 deliveries, 396 fulfilled inclusion criteria; 108 were classified with PAS at delivery. Combining the number of prior cesareans and the placental location yielded a rate ranging from 5% for one prior cesarean combined with a posterior low-lying placenta to 63% for three or more prior cesareans combined with placenta previa. The factors independently associated with PAS disorders were BMI ≥ 30, previous uterine surgery, previous postpartum hemorrhage, a higher number of prior cesareans, and a placenta previa. Finally, in this high-risk population, the rate of PAS disorders varies greatly, not only with the number of prior cesareans but also with the exact placental location and some of the women's individual characteristics. Risk stratification is thus possible in this population.

A sonographic endometrial thickness <7 mm in women undergoing in vitro fertilization increases the risk of placenta accreta spectrum

BACKGROUND

The prevalence of placenta accreta spectrum, a potentially life-threatening condition, has exhibited a significant global rise in recent decades. Effective screening methods and early identification strategies for placenta accreta spectrum could enable early treatment and improved outcomes. Endometrial thickness plays a crucial role in successful embryo implantation and favorable pregnancy outcomes. Extensive research has been conducted on the impact of endometrial thickness on assisted reproductive technology cycles, specifically in terms of pregnancy rates, live birth rates, and pregnancy loss rates. However, limited knowledge exists regarding the influence of endometrial thickness on placenta accreta spectrum.

OBJECTIVE

This study aimed to evaluate the association between preimplantation endometrial thickness and the occurrence of placenta accreta spectrum in women undergoing assisted reproductive technology cycles.

STUDY DESIGN

A total of 4637 women who had not undergone previous cesarean delivery and who conceived by in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment and subsequently delivered at the Third Affiliated Hospital of Guangzhou Medical University between January 2008 and December 2020 were included in this study. To explore the relationship between endometrial thickness and placenta accreta spectrum, we used smooth curve fitting, threshold effect, and saturation effect analysis. Multivariate logistic regression analysis was performed to evaluate the independent association between endometrial thickness and placenta accreta spectrum while adjusting for potential confounding factors. Propensity score matching was performed to reduce the influence of bias and unmeasured confounders. Furthermore, we used causal mediation effect analysis to investigate the mediating role of endometrial thickness in the relationship between gravidity and ovarian stimulation protocol and the occurrence of placenta accreta spectrum.

RESULTS

Among the 4637 women included in this study, pregnancies with placenta accreta spectrum (159; 3.4%) had significantly thinner endometrial thickness (non-placenta accreta spectrum, 10.08±2.04 mm vs placenta accreta spectrum, 8.88±2.21 mm; P<.001) during the last ultrasound before embryo transfer. By using smooth curve fitting, it was found that changes in endometrial thickness had a significant effect on the incidence of placenta accreta spectrum up to a thickness of 10.9 mm, beyond which the effect plateaued. Then, the endometrial thickness was divided into the following 4 groups: ≤7, >7 to ≤10.9, >10.9 to ≤13, and >13 mm. The absolute rates of placenta accreta spectrum in each group were 11.91%, 3.73%, 1.35%, and 2.54%, respectively. Compared with women with an endometrial thickness from 10.9 to 13 mm, the odds of placenta accreta spectrum increased from an adjusted odds ratio of 2.27 (95% confidence interval, 1.33-3.86) for endometrial thickness from 7 to 10.9 mm to an adjusted odds ratio of 7.15 (95% confidence interval, 3.73-13.71) for endometrial thickness <7 mm after adjusting for potential confounding factors. Placenta previa remained as an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 11.80; 95% confidence interval, 7.65-18.19). Moreover, endometrial thickness <7 mm was still an independent risk factor for placenta accreta spectrum (adjusted odds ratio, 3.91; 95% confidence interval, 1.57-9.73) in the matched cohort after PSM. Causal mediation analysis revealed that approximately 63.9% of the total effect of gravidity and 18.6% of the total effect of ovarian stimulation protocol on placenta accreta spectrum were mediated by endometrial thickness.

CONCLUSION

The findings of our study indicate that thin endometrial thickness is an independent risk factor for placenta accreta spectrum in women without previous cesarean delivery undergoing assisted reproductive technology treatment. The clinical significance of this risk factor is slightly lower than that of placenta previa. Furthermore, our results demonstrate that endometrial thickness plays a significant mediating role in the relationship between gravidity or ovarian stimulation protocol and placenta accreta spectrum.

Outcomes of cesarean delivery in placenta accreta: conservative delivery vs. cesarean hysterectomy

OBJECTIVES

To compare delivery outcomes of pregnancies diagnosed with placenta-accreta-syndrome (PAS) who underwent conservative treatment to patients who underwent cesarean hysterectomy.

METHODS

A retrospective study of all women diagnosed with PAS treated in one tertiary medical center between 03/2011 and 11/2020 was performed. Comparison was made between conservative management during cesarean delivery and cesarean hysterectomy. Conservative management included leaving uterus in situ with/without placenta and with/without myometrial resection.

RESULTS

A total of 249 pregnancies (0.25 % of all deliveries) were diagnosed with PAS, 208 underwent conservative cesarean delivery and 41 had cesarean hysterectomy, 31 of them were unplanned (75.6 %). The median number of previous cesarean deliveries was significantly higher in the cesarean hysterectomy group. There was no difference in the duration from the last cesarean delivery, the presence of placenta previa, pre-operative hemoglobin or platelets levels between the pregnancies with conservative management and the cesarean hysterectomy. Significantly more pregnancies with sonographic suspicion of placenta percreta and bladder invasion had cesarean hysterectomy. Cesarean hysterectomy was significantly associated with earlier delivery, with bleeding and required significantly more blood products. There was no statistically significant difference in the rate of relaparotomy following cesarean delivery or the rate of infections. Multivariable-regression-analysis revealed a significant odds ratio of 3.38 of blood loss of >3,000 mL following cesarean hysterectomy.

CONCLUSIONS

Conservative management in delivery of PAS pregnancies is associated with less bleeding complications during surgery compared to cesarean hysterectomy.

Placental volume as a novel sign for identifying placenta accreta spectrum in pregnancies with complete placenta previa

BACKGROUND

Placenta accreta spectrum (PAS) carries an increased risk of maternal-fetal mortality and morbidity, and magnetic resonance imaging (MRI) features for PAS have been used for preoperative identification. This study aims to investigate the role of placental volume evaluated by MRI in identifying PAS in pregnant women with complete placenta previa.

METHODS

Totally 163 cases of complete placenta previa pregnant women with a history of cesarean section underwent MRI for suspected PAS were included. We categorized the patients into two groups according to the presence or absence of PAS, and the maternal-fetal perinatal outcomes and placental volume analyzed by 3D Slice software were compared.

RESULTS

There were significantly more gravidity, parity, and number of previous cesarean delivery in the PAS group (P < 0.05). Significant differences were also found between the two groups with respect to the following baseline characteristics: gestational age at delivery, intraoperative blood loss, blood transfusion, and neonatal birth weight (P < 0.05). Of 163 women in the study, 7 (4.294%) required cesarean hysterectomy for high-grade PAS or pernicious bleeding during cesarean section, and PAS was confirmed with histologic confirmation in 6 (85.714%) cases. The placental volume in PAS group was greater than that in the non-PAS group (P < 0.05). With a threshold of more than 887 cm3, the sensitivity and specificity in identifying PAS were 85.531% and 83.907% respectively, with AUC 0.908 (95% CI: 0.853-0.948).

CONCLUSIONS

Placental volume may be a promising indicator of PAS in complete placenta previa patients with a history of cesarean section.

Incidence and risk factors for severe postpartum haemorrhage in women with anterior low-lying or praevia placenta and prior caesarean: Prospective population-based study

OBJECTIVE

To assess the incidence and risk factors for severe postpartum haemorrhage (PPH) in women with an anterior low-lying or praevia placenta, prior caesarean and no prenatal suspicion of placenta accreta spectrum (PAS).

DESIGN

Population-based study in 176 maternity units in France.

POPULATION

All women with anterior low-lying (0-19 mm from the cervical internal os) or praevia placenta, diagnosed prospectively before birth, prior caesarean and no prenatal suspicion of PAS.

METHODS

Multivariable logistic regression to identify risk factors for severe PPH in the main population and after exclusion of women with PAS diagnosed only at birth.

MAIN OUTCOME MEASURES

Severe PPH defined by a composite criterion either estimated blood loss of ≥1500 ml, transfusion of ≥4 or more units of packed red blood cells, embolisation or surgical treatment.

RESULTS

Of the 520 114 women constituting the source population, 230 (0.44/1000 women; 95% confidence interval [CI] 0.38-0.50) met the inclusion criteria. Severe PPH rate was 24.8% (95% CI 19.2-30.4) overall, 27.5% (95% CI 21.8-33.3) in women with placenta praevia and 15.4% (95% CI 10.7-20.0) in women with low-lying placenta. PAS was diagnosed at birth in 22 women (9.9%; 95% CI 5.8-13.4), although previously unsuspected. After their exclusion, severe PPH incidence was 17.3% (95% CI 12.4-22.2). In multivariate analysis, the only factor associated with a higher severe PPH risk was placenta previa (aOR, 3.65; 95%CI, 1.20-15.8).

CONCLUSION

Severe PPH is frequent among women with anterior low-lying or praevia placenta and prior caesarean, even after exclusion of women with PAS. The risk of severe PPH for those with praevia is nearly twice that with low-lying placenta.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part I: Obstetric (Non-Fetal) Complications

Acute abdominopelvic pain in pregnant and postpartum patients presents clinical and therapeutic challenges, often requiring quick and accurate imaging diagnosis. Ultrasound remains the primary imaging investigation. Magnetic resonance imaging (MRI) has been shown to be a powerful diagnostic tool in the setting of acute abdominal pain during pregnancy and puerperium. MRI overcomes some drawbacks of US, avoiding the ionizing radiation exposure of a computed tomography (CT) scan. Although CT is not usually appropriate in pregnant patients, it is crucial in the emergency evaluation of postpartum complications. The aim of this article is to provide radiologists with a thorough familiarity with the common and uncommon pregnancy and puerperium abdominal emergencies by illustrating their imaging appearances. The present first section will review and discuss the imaging findings for acute abdominopelvic pain of obstetric (non-fetal) etiology.

The TGF-β/UCHL5/Smad2 Axis Contributes to the Pathogenesis of Placenta Accreta

Placenta accreta is a high-risk condition causing obstetric crisis and hemorrhage; however, its pathogenesis remains unknown. We aimed to identify the factors contributing to trophoblast invasiveness and angiogenic potential, which in turn drive the pathogenesis of placenta accreta. We focused on the transforming growth factor (TGF)-β1-Smad pathway and investigated the intrinsic relationship between the time- and dose-dependent inhibition of the ubiquitinating enzyme UCHL5 using bAP15, a deubiquitinase inhibitor, after TGF-β1 stimulation and the invasive and angiogenic potential of two cell lines, gestational choriocarcinoma cell line JEG-3 and trophoblast cell line HTR-8/SVneo. UCHL5 inhibition negatively regulated TGF-β1-induced Smad2 activation, decreasing extravillous trophoblast invasiveness. Smad1/5/9 and extracellular signal-regulated kinase (ERK) were simultaneously activated, and vascular endothelial growth factor was secreted into the trophoblast medium. However, extravillous trophoblast culture supernatant severely impaired the vasculogenic potential of human umbilical vein endothelial cells. These results suggest that the downstream ERK pathway and Smad1/5/9 potentially regulate the TGF-β1-Smad pathway in extravillous trophoblasts, whereas Smad2 contributes to their invasiveness. The abnormal invasive and angiogenic capacities of extravillous cells, likely driven by the interaction between TGF-β1-Smad and ERK pathways, underlie the pathogenesis of placenta accreta.

A risk factor profile for placenta accreta spectrum in pregnancies conceived with assisted reproductive technology

Objective

To identify independent risk factors for placenta accreta spectrum among pregnancies conceived with assisted reproductive technology.

Design

Retrospective cohort study.

Setting

Tertiary hospital.

Patients

Individuals who conceived with assisted reproductive technology and reached 20 weeks' gestation or later from 2011 to 2017.

Interventions

Patient and cycle data was abstracted from hospital records and supplemented with state-level data. Poisson regression was used for multivariate analyses and reported as adjusted relative risks (aRR).

Main Outcome Measures

Clinical or histologic placenta accreta spectrum.

Results

Of 1,975 qualifying pregnancies, 44 (2.3%) met criteria for accreta spectrum at delivery. In the multivariate model, significant risk factors included low-lying placenta at delivery (aRR, 15.44; 95% CI 7.76-30.72), uterine factor infertility or prior uterine surgery (aRR, 4.68; 95% CI, 2.72-8.05), initial low-lying placentation that resolved (aRR, 3.83; 95% CI, 1.90-7.73), and use of frozen embryos (aRR, 3.02; 95% CI, 1.66-5.48). When the fresh vs frozen variable was replaced with controlled ovarian hyperstimulation, the final model did not change (aRR, 2.40 for unstimulated cycles, 95% CI, 1.32-4.38). With frozen transfers, the accreta rate was 16% when the endometrial thickness was < 6mm vs 3.8% with thicker endometrium (P=.02).

Conclusions

Among pregnancies conceived with assisted reproductive technology, accreta spectrum is associated with low placental implantation (even when resolved), uterine factor infertility and prior uterine surgery, and the use of frozen embryo transfer or unstimulated cycles.

External Validation of a Multivariable Prediction Model for Placenta Accreta Spectrum

BACKGROUND

Placenta accreta spectrum (PAS) is a disorder of abnormal placentation associated with severe postpartum hemorrhage, maternal morbidity, and mortality. Predelivery prediction of this condition is important to determine appropriate delivery location and multidisciplinary planning for operative management. This study aimed to validate a prediction model for PAS developed by Weiniger et al in 2 cohorts who delivered at 2 different United States tertiary centers.

METHODS

Cohort A (Brigham and Women's Hospital; N = 253) included patients with risk factors (prior cesarean delivery and placenta previa) and/or ultrasound features of PAS presenting to a tertiary-care hospital. Cohort B (Columbia University Irving Medical Center; N = 99) consisted of patients referred to a tertiary-care hospital specifically because of ultrasound features of PAS. Using the outcome variable of surgical and/or pathological diagnosis of PAS, discrimination (via c-statistic), calibration (via intercept, slope, and flexible calibration curve), and clinical usefulness (via decision curve analysis) were determined.

RESULTS

The model c-statistics in cohorts A and B were 0.728 (95% confidence interval [CI], 0.662-0.794) and 0.866 (95% CI, 0.754-0.977) signifying acceptable and excellent discrimination, respectively. The calibration intercept (0.537 [95% CI, 0.154-0.980] for cohort A and 3.001 [95% CI, 1.899- 4.335] for B), slopes (0.342 [95% CI, 0.170-0.532] for cohort A and 0.604 [95% CI, -0.166 to 1.221] for B), and flexible calibration curves in each cohort indicated that the model underestimated true PAS risks on average and that there was evidence of overfitting in both validation cohorts. The use of the model compared to a treat-all strategy by decision curve analysis showed a greater net benefit of the model at a threshold probability of >0.25 in cohort A. However, no net benefit of the model over the treat-all strategy was seen in cohort B at any threshold probability.

CONCLUSIONS

The performance of the Weiniger model is variable based on the case-mix of the population with regard to PAS clinical risk factors and ultrasound features, highlighting the importance of spectrum bias when applying this PAS prediction model to distinct populations. The model showed benefit for predicting PAS in populations with substantial case-mix heterogeneity at threshold probability of >25%.

Sonographic Diagnosis and Management With Delayed Hysterectomy of Two Cesarean Scar Pregnancies That Developed Into Placenta Percreta: Two Case Reports

Approximately two-thirds of the patients with a cesarean scar pregnancy (CSP) will develop placenta accreta spectrum (PAS). PAS occurs when the placenta attaches too deeply to the uterine wall, and sometimes, the placenta can extend beyond the uterus, invading surrounding organs. PAS is commonly managed with a cesarean hysterectomy, and these deliveries are often complicated by maternal and fetal morbidity and mortality. However, delaying hysterectomy and using chemotherapeutic agents may be a safe and beneficial alternative. We describe the case of a 32 -year-old G3P2002 with a history of two prior cesarean sections (CS) who was referred to our Maternal Fetal Medicine department due to the concern of a gestational sac embedded in the anterior uterine wall in the cesarean scar. Magnetic resonance imaging (MRI) findings at 33 weeks confirmed that the patient had developed placenta percreta extending into the sigmoid colon. We also describe the case of a 30-year-old G6P4104 with a history of four prior CS who was referred to our department for concern of a pregnancy complicated by CSP. This patient had an MRI performed at 23 weeks that showed placenta percreta invading the bladder. Patients one and two were managed with a staged procedure, with CS followed by a delayed laparoscopic and abdominal hysterectomy, respectively, to minimize bowel and bladder injury. After the CS, the patients subsequently received a five-day course of intravenous (IV) etoposide 100mg/m2, and at six weeks postpartum, the patients had a hysterectomy, both showing resolution of the placenta invasion into the surrounding organs on postpartum MRI and confirmed by tissue pathology reports. Our cases present the challenge in diagnosis and management of the most severe presentation of PAS that varies from the generally accepted management recommendations. Delayed hysterectomy with chemotherapy can be a reasonable, conservative surgical approach in the most severe types of PAS. As in our cases, this management could improve maternal and fetal morbidity and mortality.

Circulating microparticle proteins predict pregnancies complicated by placenta accreta spectrum

Placenta accreta spectrum (PAS) is characterized by abnormal attachment of the placenta to the uterus, and attempts at placental delivery can lead to catastrophic maternal hemorrhage and death. Multidisciplinary delivery planning can significantly improve outcomes; however, current diagnostics are lacking as approximately half of pregnancies with PAS are undiagnosed prior to delivery. This is a nested case-control study of 35 cases and 70 controls with the primary objective of identifying circulating microparticle (CMP) protein panels that identify pregnancies complicated by PAS. Size exclusion chromatography and liquid chromatography with tandem mass spectrometry were used for CMP protein isolation and identification, respectively. A two-step iterative workflow was used to establish putative panels. Using plasma sampled at a median of 26 weeks' gestation, five CMP proteins distinguished PAS from controls with a mean area under the curve (AUC) of 0.83. For a separate sample taken at a median of 35 weeks' gestation, the mean AUC was 0.78. In the second trimester, canonical pathway analyses demonstrate over-representation of processes related to iron homeostasis and erythropoietin signaling. In the third trimester, these analyses revealed abnormal immune function. CMP proteins classify PAS well prior to delivery and have potential to significantly reduce maternal morbidity and mortality.

Placenta Accreta Spectrum Diagnosis Challenges and Controversies in Current Obstetrics: A Review

Background

Placenta accreta spectrum (PAS) is the most common obstetric complication in current obstetrics in which the placenta is fully or partially attached to the uterine myometrial layer at delivery. This is commonly due to the deficiency of the uterine interface between the uterine endometrial and myometrial layers leading to abnormal decidualization at the uterine scar area, which permits the abnormally placental anchoring villous and trophoblasts, deeply invade the myometrium. The prevalence of PAS is globally at rising trends every day in modern obstetrics originally due to the high increasing rate of cesarean sections, placenta previa, and assisted reproductive technology (ART). Thus, the early and precise diagnosis of PAS is imperative to prevent maternal intrapartum or postpartum bleeding complications.

Objective

The main aim of this review is to debate the current challenges and controversies in the routine diagnosis of PAS diseases in obstetrics.

Data Source

We retrospectively reviewed the recent articles on different methods of diagnosing PAS in PubMed, Google Scholar, Web of Science, Medline, Embase, and other website databases.

Results

Despite that, the standard ultrasound is a reliable and key tool for the diagnosis of PAS, the lack of ultrasound features does not exclude the diagnosis of PAS. Therefore, clinical assessment of risk factors, MRI tests, serological markers, and placental histopathological tests are also indispensable for the prediction of PAS. Previously, limited studies reached a high sensitivity rate of diagnosis PAS in appropriate cases, while many studies recommended the inclusion of different diagnosis methods to improve the diagnosis accuracy.

Conclusion

A multidisciplinary squad with well-experienced obstetricians, radiologists, and histopathologists should be involved in the establishment of the early and conclusive diagnosis of PAS.

Clinical Correlates of Placenta Accreta Spectrum Disorder Depending on the Presence or Absence of Placenta Previa: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate whether there are differences in risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa.

DATA SOURCES

We performed a systematic search in Medline, EMBASE, ClinicalTrials.gov , and Web of Science from inception through April 25, 2022, without language or date restrictions. Search strategy included the key words "placenta accreta," "placenta increta," "placenta percreta," "adherent placenta," "invasive placenta," "abnormal placent*," "placenta previa," and "marginal placent*."

METHODS OF STUDY SELECTION

Of the 1,122 articles screened, seven studies were included in the final review. Studies were included if they compared the risk factors and maternal outcomes of pregnancies complicated by placenta accreta spectrum depending on the presence or absence of placenta previa.

TABULATION, INTEGRATION, AND RESULTS

A random-effects model was used to pool the mean differences or odds ratios (OR) and the corresponding 95% CIs using RevMan software. A total of 3,342 pregnancies complicated by placenta accreta spectrum were included in the meta-analysis (2,365 without previa and 977 with previa). Pregnancies complicated by placenta accreta spectrum without previa were more likely to have been conceived by in vitro fertilization (IVF) (OR 3.11, 95% CI 1.93-5.02, P <.001, I 2 =52.0%) and to be associated with prior dilation and curettage (D&C) (OR 1.60, 95% CI 1.15-2.22, P =.005, I 2 =0.0%) and myomectomy (OR 2.47, 95% CI 1.31-4.66, P =.005, I 2 =0.0%), but they were less likely to be associated with prior cesarean delivery (OR 0.15, 95% CI 0.06-0.37, P <.001, I 2 =87.0%). Placenta accreta spectrum without previa was less likely to be diagnosed antenatally (OR 0.07, 95% CI 0.04-0.11, P <.001, I 2 =38.0%). Also, women with pregnancies without previa had lower rates of red blood cell transfusion, intensive care unit admission, risk of hysterectomy, unscheduled delivery, and intraoperative bowel or bladder injuries.

CONCLUSION

Pregnancies complicated by placenta accreta spectrum without previa had a more prominent association with IVF and prior D&C and myomectomy but were much less likely to be associated with prior cesarean delivery. Further, placenta accreta spectrum without previa was less likely to be diagnosed antenatally, although it had better maternal outcomes as compared with placenta accreta spectrum with previa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022307637.

Percreta score to differentiate between placenta accreta and placenta percreta with ultrasound and MR imaging

INTRODUCTION

The objective of this study was to assess the performance of ultrasound and magnetic resonance imaging (MRI) features in helping to classify the type of placenta accreta spectrum (PAS; accreta/increta vs percreta), alone or combined in a predictive score.

MATERIAL AND METHODS

We conducted a retrospective study in 82 pregnant women with PAS who underwent ultrasound and MRI examination of the pelvis before delivery (from an initial cohort of 185 women with PAS). We estimated the sensitivity, specificity and accuracy of MRI and ultrasound in the diagnosis of the type of PAS. We analyzed cesarean and imaging features using univariable logistic regression analysis. We constructed a nomogram to predict the risk of placenta percreta and validated it with bootstrap resampling, then used receiver operating characteristic curves to assess the performance of the model in distinguishing between placenta percreta and placenta accreta/increta.

RESULTS

Among the 82 patients, 29 (35%) had placenta accreta/increta and 53 (65%) had placenta percreta. The best features to discriminate between placenta accreta/increta and placenta percreta with ultrasound were increased vascularization at the uterine serosa-bladder wall interface (odds ratio [OR] 7.93; 95% confidence interval [CI] 2.78-24.99; p < 0.01) and the number of lacunae without a hyperechogenic halo (OR 1.36; 95% CI 1.14-1.67; p = 0.012). Concerning MRI markers, heterogeneous placenta (OR 12.89; 95% CI 3.05-89.16; p = 0.002), dark intraplacental bands (OR 12.89; 95% CI 3.05-89.16; p = 0.002) and bladder wall interruption (OR 15.89; 95% CI 4.78-73.33; p < 0.001) had a higher OR in discriminating placenta accreta/increta from placenta percreta. The nomogram yielded areas under the curve of 0.841 (95% CI 0.754-0.927) and 0.856 (95% CI 0.767-0.945), after bootstrap resampling, for the accurate prediction of placenta percreta.

CONCLUSIONS

The nomogram we developed to predict the risk of placenta percreta among patients with PAS had good discriminative capabilities. This performance and its impact on maternal morbidity should be confirmed by future prospective studies.

Conservative management or cesarean hysterectomy for placenta accreta spectrum: the PACCRETA prospective study

BACKGROUND

Placenta accreta spectrum is a life-threatening condition that has increased dramatically in recent decades along with cesarean rates worldwide. Cesarean hysterectomy is widely practiced in women with placenta accreta spectrum; however, the maternal outcomes after cesarean hysterectomy have not been thoroughly compared with the maternal outcomes after alternative approaches, such as conservative management.

OBJECTIVE

This study aimed to compare the severe maternal outcomes between women with placenta accreta spectrum treated with cesarean hysterectomy and those treated with conservative management (leaving the placenta in situ).

STUDY DESIGN

From a source population of 520,114 deliveries in 176 hospitals (PACCRETA study), we designed an observational cohort of women with placenta accreta spectrum who had either a cesarean hysterectomy or a conservative management (the placenta left in situ) during cesarean delivery. Clinicians prospectively identified women meeting the inclusion criteria and included them at delivery. Data collection started only after the women had received information and agreed to participate in the study in the immediate postpartum period. The primary outcome was the transfusion of >4 units of packed red blood cells within 6 months after delivery. Secondary outcomes were other maternal complications within 6 months. We used propensity score weighting to account for potential indication bias.

RESULTS

Here, 86 women had conservative management and 62 women had cesarean hysterectomy for placenta accreta spectrum during cesarean delivery. The primary outcome occurred in 14 of 86 women in the conservative management group (16.3%) and 36 of 61 (59.0%) in the cesarean hysterectomy group (risk ratio in propensity score weighted model, 0.29; 95% confidence interval, 0.19-0.45). The rates of hysterectomy, total estimated blood loss exceeding 3000 mL, any blood product transfusion, adjacent organ injury, and nonpostpartum hemorrhage-related severe maternal morbidity were lower with conservative management than with cesarean hysterectomy (all adjusted, P≤.02); but, the rates of arterial embolization, endometritis, and readmission within 6 months of discharge were higher with conservative management than with cesarean hysterectomy.

CONCLUSION

Among women with placenta accreta spectrum who underwent cesarean delivery, conservative management was associated with a lower risk of transfusion of >4 units of packed red blood cells within 6 months than cesarean hysterectomy.

Placenta accreta spectrum - variations in clinical practice and maternal morbidity between the UK and France: a population-based comparative study

Objective

To compare the management and outcomes of women with placenta accreta spectrum (PAS) in France and the UK.

Design

Two population‐based cohorts.

Setting

All obstetrician‐led hospitals in the UK and maternity hospitals in eight French regions.

Population

A cohort of 219 women with PAS in France and a cohort of 154 women with PAS in the UK.

Methods

The management and outcomes of women with PAS were compared between the UK and France.

Main outcome measures

Median blood loss, severe postpartum haemorrhage (≥3 l), postpartum infection and damage to surrounding organs.

Results

The management of PAS differed between the two countries: a larger proportion of women with PAS in the UK had a caesarean hysterectomy compared with France (43% vs 26%, p < 0.001), whereas in France a larger proportion of women with PAS received a uterus‐preserving approach compared with the UK (36% vs 19%, p < 0.001). The total median blood loss in the UK was 3 l (IQR 1.7–6.5 l), compared with 1 l (IQR 0.5–2.5 l) in France; more women with PAS had a severe postpartum haemorrhage (PPH) in the UK compared with women with PAS in France (58% vs 21%, p < 0.001) [Correction added on 06 May 2022, after first online publication: ‘24 hour’ has been changed to ‘total’ in the preceding sentence]. There was no difference between the UK and French populations for postpartum infection or organ damage.

Conclusions

The UK and France have very different approaches to managing PAS, with more women in France receiving a uterine‐conserving approach and more women in the UK undergoing caesarean hysterectomy. A life‐threatening haemorrhage was more common in the UK than in France, which may be the result of differential management and/or the organisation of the healthcare systems.

In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France.

Tweetable abstract

In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France.

In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France.

Linked article: This article is commented on by Amarnath Bhide, pp. 1686 in this issue. To view this minicommentary visit https://doi.org/10.1111/1471-0528.17170.

Characteristics and outcomes of pregnant women with placenta accreta spectrum in Italy: A prospective population-based cohort study

Introduction

Placenta accreta spectrum (PAS) is a rare but potentially life-threatening event due to massive hemorrhage. Placenta previa and previous cesarean section are major risk factors for PAS. Italy holds one of the highest rates of primary and repeated cesarean section in Europe; nonetheless, there is a paucity of high-quality Italian data on PAS. The aim of this paper was to estimate the prevalence of PAS in Italy and to evaluate its associated factors, ante- and intra-partum management, and perinatal outcomes. Also, since severe morbidity and mortality in Italy show a North-South gradient, we assessed and compared perinatal outcomes of women with PAS according to the geographical area of delivery.

Material and methods

This was a prospective population-based study using the Italian Obstetric Surveillance System (ItOSS) and including all women aged 15–50 years with a diagnosis of PAS between September 2014 and August 2016. Six Italian regions were involved in the study project, covering 49% of the national births. Cases were prospectively reported by a trained clinician for each participating maternity unit by electronic data collection forms. The background population comprised all women who delivered in the participating regions during the study period.

Results

A cohort of 384 women with PAS was identified from a source population of 458 995 maternities for a prevalence of 0.84/1000 (95% CI, 0.75–0.92). Antenatal suspicion was present in 50% of patients, who showed reduced rates of blood transfusion compared to unsuspected patients (65.6% versus 79.7%, P = 0.003). Analyses by geographical area showed higher rates of both concomitant placenta previa and prior CS (62.1% vs 28.7%, P<0.0001) and antenatal suspicion (61.7% vs 28.7%, P<0.0001) in women in Southern compared to Northern Italy. Also, these women had lower rates of hemorrhage ≥2000 mL (29.6% vs 51.2%, P<0.0001), blood transfusion (64.5% vs 87.5%, P = 0.001), and severe maternal morbidity (5.0% vs 11.1%, P = 0.036). Delivery in a referral center for PAS occurred in 71.9% of these patients.

Conclusions

Antenatal suspicion of PAS is associated with improved maternal outcomes, also among high-risk women with both placenta previa and prior CS, likely because of their referral to specialized centers for PAS management.

Management practices for placenta accreta spectrum patients: a Latin American hospital survey

INTRODUCTION

Placenta accreta spectrum (PAS) causes severe morbidity and can result in maternal death. It must be managed in specialized centers with interdisciplinary groups, but few publications have described the usual management within a specific geographic region. We intend to describe the usual approach for PAS in reference centers in Latin America.

METHODOLOGY

This was an observational, multicenter, cross-sectional study conducted in Latin American PAS reference centers. A standardized survey was implemented and applied to obstetric service coordinators and leaders of interdisciplinary groups with experience in PAS between September and November 2020.

RESULTS

One hundred fifty-four hospitals were included. Most of them (64.3%) handle approximately one case of PAS every two months, and almost all centers (89.6%) believe that their performance could be improved.

CONCLUSIONS

Most of the reference centers for PAS in Latin America attend to a small number of cases each year, and almost all of these hospitals identify opportunities to improve the management or approach for PAS in women.